Using reliable data from 34 countries for the years 1950, 1960, 1970 and 1980 it was observed that the proportional mortality ratio for 50 years of age and above, proposed by Swaroop & Uemura, did not provide the best discriminatory power between more and less developed countries in any of the years studied. In 1970 and 1980, the greatest discriminatory power was obtained by using the proportional mortality ratio for 75 years of age and above. The displacement of deaths to upper age groups over a certain period of time was better translated by variations in the 75 years and above than in the 50 years and above proportional mortality ratio. It is also useful to complement this information by computing the percentage of deaths at 65 years of age and above. It is suggested that the classes proposed by Swaroop & Uemura should be reformulated using new classes based on the proportional mortality ratio for 75 years and above, with the following limits: 0 | 20; 20 | 40; 40 | 50; 50 | 55 and 55 and above, with the possibility of subdividing the last group, if necessary, in the future.